About to install solar. What about existing tanks?

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nonsequitir

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My house is about 20 yrs old and fortunately the rear aspect is almost due south so solar makes sense and we're pursuing that.

The existing water system has two coffin-like tanks in the attic. They're not covered and they're pretty swampy. One of the tanks (I guess it's an overflow) is pretty gross and has a scum on the water (i.e., it looks like the water there hasn't budged in a long time) .

My question is this... Should these tanks be replaced, or removed, cleaned and re-seated? Or should I just get new tanks that are sealed? Is any of this worth the effort or cost? Any idea of the costs involved?
 
They should certainly be cleaned, covered and insulated - any idea why they were left in their current state?
 
mathepac said:
They should certainly be cleaned, covered and insulated - any idea why they were left in their current state?
Click to expand...

I really don't know, I suspect that these were installed prior to building regulation changes. Are the tank coverings typically airtight? And is the identical overflow tank needed at all? The main tank has an overflow outlet pipe which comes out from the back of the house.
 
have you an open vented heating system? if yes, then one of those tanks service the heating.
covers aren't air tight, turn off mains water, open bath taps to drain tank, then clean the crap out with a wet vac or brush and shovel. then rinse and refill. no need to disconnect tanks.
Cover tanks with some aeroboard or ply, you can buy a plastic cover for those coffin tanks.
 
From my very basic understanding of plumbing, I think it's an open vented system. When you say the 2nd tanks "services" the heating, do you mean keep it topped up and under a gravity-based pressure?

Thanks for the cleaning how-to, I'll give it a go this evening.
 
yes, there will also be a vent pipe over the tank to allow the system to expand when hot. this water will look dirty because it is, that might be the same water in the tank for many years/months because unlike your plumbing water it isn't constantly refreshed.
I wouldn't bother cleaning out the heating header tank, I would however clean the plumbing storage tank out.
 
Thanks DavyJones. Does dirty water in the heating tank reduce efficiency? Would you ever add a solution to it to improve the condition of the radiators it services?
 
You don't have to do anything with the existing tanks...

Water is mixed with antifreeze and added to the solar panels via the pumping station, usually situated in the hot press. You may require a stainless steel cylinder if you don't already have one.
 
you can add a cleanser to the system, leave it for a few weeks and then flush out. Once it is flushed out you can then add an inhibitor to protect system. Fernox make a range of products for heating system.
To add cleanser do the following:
Tie up ballcock or turn off mains,
drain down the heating system, through a vent nipple on rad or drain off cock.
you only really want the header tank to empty so don't drain off too much.
add cleanser/desludger.
since you have drained off a bit of the system this allows the agent to enter pipework,
untie ballcock/turn on mains.
When you flush it out a couple of weeks later, empty entire system through drain off cock and when you are refilling just add in the inhibitor.
 
weejasy77 said:
You don't have to do anything with the existing tanks...

Water is mixed with antifreeze and added to the solar panels via the pumping station, usually situated in the hot press. You may require a stainless steel cylinder if you don't already have one.
Click to expand...


Since his water is "swampy", then it's better he cleans the tank.
With regard to the solar panels they don't have much to do with them although they will fill the cylinder that the panels indirectly heat.

You will need to change your cylinder for a dual coil type. the circuit from panels to cylinder will be indepedant from the rest of the heating system and will be pressurised.
 
DavyJones said:
Since his water is "swampy", then it's better he cleans the tank.
With regard to the solar panels they don't have much to do with them although they will fill the cylinder that the panels indirectly heat.

You will need to change your cylinder for a dual coil type. the circuit from panels to cylinder will be indepedant from the rest of the heating system and will be pressurised.
Click to expand...

The solar installation will come with a new factory sealed 300 ltr tank and its own expansion vessel. I'm going to clean the existing tanks anyway - it'd make the bath water a little less yellow!
 
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